1. Field of the Invention
The present invention relates to dishwashers, and more particularly, to a dishwasher which can control a flow of washing water conveniently, and effectively.
2. Discussion of the Related Art
In general, the dishwasher washes dishes automatically. Since the dishwasher washes, rinses, dries, and stores the dishes, the dishwasher can reduce domestic work.
In washing methods of the dishwasher, there is a shower type, and a ultrasonic type, of which shower type is used widely in home. In the shower type, warm water having detergent dissolved therein is sprayed to the dishes on racks for washing. The water is sprayed by a propeller, or nozzles in a rotating pipe.
A related art dishwasher will be described briefly, with reference to FIG. 1.
The related art dishwasher is provided with a water holding part 1, and upper, and lower washing parts 3, and 4, for spraying water introduced thereto from the water holding part, respectively.
The water holding part 1 has a main water collecting part 1a for receiving water from an outside of the dishwasher, and collecting and discharging contaminated water after washing the dishes. Over the main water collecting part 1a, there is a channel forming part 1b having flow passages formed therein for moving washing water circulating within the dishwasher to the upper, and lower washing parts. The channel forming part 1b has a filtering part 1c connected thereto for filtering contaminants from the washing water.
The motor 2 provides power for driving a washing pump for supplying the washing water to the upper and the lower washing parts 3, and 4 during dishwashing, or driving a discharge pump for discharging the washing water after finish of the washing.
The upper, and lower washing parts 3, and 4, places for washing the dishes actually, are connected to the water holding part with connection pipes. Spray arms (not shown) of the upper, and lower washing parts 3, and 4 spray the washing water supplied from the water holding part 1, to wash the dishes.
The steps of a process for operating the related art dishwasher will be described.
After placing dishes intended to wash in the rack, a cycle the user desires is entered. Then, the washing water is filled in the main water collection part of the dishwasher through a water supply valve connected to an outside of the dishwasher. Then, the dishwasher puts a heater into operation, to heat the washing water, and puts the motor into operation, to drive the washing pump. Then, the heated washing water moves to the upper, and lower spray arms through the connection pipes by the washing pump. The washing water reached to the spray arms is sprayed through the spray nozzles, and removes contaminants from a surface of the dish.
The contaminants and the washing water removed from the dishes after the dishwashing are collected to the main collection part. If a level of contamination of the washing water is higher than a certain level, the dishwasher discharges the contaminated washing water through the discharge pump, and has fresh water received from an outside of the dishwasher. However, if the level of the contamination is below the certain level, the dishwasher cleans the washing water collected at the main collection part, and supplies to the upper and lower spray arms by using the washing pump, again. The washing water collected at the main collection part after finish of washing is discharged to an outside of the dishwasher by the discharge pump, together with the contaminants.
In the meantime, the related art dishwasher is provided with a three-way valve for controlling a direction of the washing water, mostly a solenoid valve. The solenoid valves, opened/closed automatically by an electro-magnetic principle, are widely used in automation of complicated machines, or safety devices.
However, the related art dishwasher has the following problems.
First, the related art dishwasher supplies the washing water to the upper, and lower spray arms at the same time when washing is performed at the upper washing part and the lower washing part. According to this, it is liable to use the washing water excessively, to fail effective control of the washing water.
Second, the related art dishwasher has a complicated mounting structure of a flow control device which controls a direction of the washing water.